Musnad Ahmad 2419

It was narrated that Ibn 'Abbas said concerning the words of the jinn, “... when the Devotee of Allah stands forth to invoke Him, they just make round him a dense crowd” [al-Jinn 72:19]. When they saw him leading his Companions in prayer, and they were following his prayer, bowing when he bowed and prostrating when he prostrated, they were amazed at how his Companions obeyed him. When they went back to their companions they said: When the slave (devotee) of Allah - meaning the Prophet (ﷺ) - stood up invoking Him, they made round him a dense crowd.